What sound does a rainbow make: Raising a baby after another was taken by SIDS

It is getting later in the evening, and the quiet is setting in.  The dogs are cuddling up, while the frogs have not yet started their evening choir practice.  We live in a quiet little town, so there is little traffic noise other than the blaring horn of the passing evening train.  It is calm, it is peaceful, and yet my ears are straining to hear something. What sound could I possibly be listening so hard for?  After a loud and crazy day alone with my children, you would think I would savor the silence.  As a mom of an Angel, silence is also one of my biggest fears.
Amidst the peace and quiet that fills my home tonight, is also a feeling of dread.  My son is five months old tomorrow, and is just beginning to sleep in his own room.  I am frequently going into his room and checking him for signs of life.  Is he breathing, does he feel cold?  Will he be OK the next time I go to check on him?  All of these questions run through my mind as I listen for that cherished breath, keep my ears tuned in for a whimper or rustle when I am out of the room.
This little rainbow child was brught into the world under less than ideal circumstances.  He was born six weeks early due to my placenta tearing and having an "emergency c-section".  He spent two weeks in the NICU and about a month on oxyen once we came home.  Five months later,  I am still listening, dreading the silence that comes with lifes biggest cruelties.
My daughter was one week shy of six months old when she passed, peacefully and quietly in her sleep.  I remember it, I feel it as if it were yesterday.  Today my life is crazy, it is noisy, it is many times simply chaos.  Remembering my daughter in life, and not just in her death I realize something else.  My rainbow child has so many other noisy blessings to bring into the life of my family.  He coos and giggles, he cries like he has an hidden extra lung.  He brings giggles and smiles to his big brother and sister, and puts a song in my heart.
The question was; what sound does a rainbow make?  The answer is that he makes more sounds than colors in a rainbow.  While I worry the days away, I also take time to truly cherish every moment of my children's lives in a way few other parents can.